Buggy code:
public abstract class Openable extends JavaElement implements IBufferChangedListener , IOpenable { protected Openable ( JavaElement parent ) { } public void bufferChanged ( BufferChangedEvent event ) { } protected abstract boolean buildStructure ( OpenableElementInfo info , IProgressMonitor pm , Map newElements , IResource underlyingResource ) throws JavaModelException { } public boolean canBeRemovedFromCache ( ) { } public boolean canBufferBeRemovedFromCache ( IBuffer buffer ) { } protected void closeBuffer ( ) { } protected void closing ( Object info ) { } protected void codeComplete ( ICompilationUnit cu , ICompilationUnit unitToSkip , int position , CompletionRequestor requestor , WorkingCopyOwner owner , ITypeRoot typeRoot ) throws JavaModelException { } protected IJavaElement [ ] codeSelect ( ICompilationUnit cu , int offset , int length , WorkingCopyOwner owner ) throws JavaModelException { PerformanceStats performanceStats = ( SelectionEngine . PERF ) ? PerformanceStats . getStats ( JavaModelManager . SELECTION_PERF , this ) : null ; if ( performanceStats != null ) { performanceStats . startRun ( ( ( ( ( ( ( new String ( cu . getFileName ( ) ) ) + "<seq2seq4repair_space>at<seq2seq4repair_space>[" ) + offset ) + "," ) + length ) + "]" ) ) ; } JavaProject project = ( ( JavaProject ) ( getJavaProject ( ) ) ) ; SearchableEnvironment environment = project . newSearchableNameEnvironment ( owner ) ; SelectionRequestor requestor = new SelectionRequestor ( environment . nameLookup , this ) ; IBuffer buffer = getBuffer ( ) ; if ( buffer == null ) { return requestor . getElements ( ) ; } int end = buffer . getLength ( ) ; if ( ( ( offset < 0 ) || ( length < 0 ) ) || ( ( offset + length ) > end ) ) { throw new JavaModelException ( new JavaModelStatus ( IJavaModelStatusConstants . INDEX_OUT_OF_BOUNDS ) ) ; } <START_BUG> SelectionEngine engine = new SelectionEngine ( environment , requestor , project . getOptions ( true ) ) ; <END_BUG> engine . select ( cu , offset , ( ( offset + length ) - 1 ) ) ; if ( performanceStats != null ) { performanceStats . endRun ( ) ; } if ( NameLookup . VERBOSE ) { System . out . println ( ( ( ( ( Thread . currentThread ( ) ) + "<seq2seq4repair_space>TIME<seq2seq4repair_space>SPENT<seq2seq4repair_space>in<seq2seq4repair_space>NameLoopkup#seekTypesInSourcePackage:<seq2seq4repair_space>" ) + ( environment . nameLookup . timeSpentInSeekTypesInSourcePackage ) ) + "ms" ) ) ; System . out . println ( ( ( ( ( Thread . currentThread ( ) ) + "<seq2seq4repair_space>TIME<seq2seq4repair_space>SPENT<seq2seq4repair_space>in<seq2seq4repair_space>NameLoopkup#seekTypesInBinaryPackage:<seq2seq4repair_space>" ) + ( environment . nameLookup . timeSpentInSeekTypesInBinaryPackage ) ) + "ms" ) ) ; } return requestor . getElements ( ) ; } protected Object createElementInfo ( ) { } public boolean exists ( ) { } public String findRecommendedLineSeparator ( ) throws JavaModelException { } protected void generateInfos ( Object info , HashMap newElements , IProgressMonitor monitor ) throws JavaModelException { } public IBuffer getBuffer ( ) throws JavaModelException { } public IBufferFactory getBufferFactory ( ) { } protected BufferManager getBufferManager ( ) { } public IResource getCorrespondingResource ( ) throws JavaModelException { } public IOpenable getOpenable ( ) { } public IResource getUnderlyingResource ( ) throws JavaModelException { } protected boolean hasBuffer ( ) { } public boolean hasUnsavedChanges ( ) throws JavaModelException { } public boolean isConsistent ( ) { } public boolean isOpen ( ) { } protected boolean isSourceElement ( ) { } public boolean isStructureKnown ( ) throws JavaModelException { } public void makeConsistent ( IProgressMonitor monitor ) throws JavaModelException { } public void open ( IProgressMonitor pm ) throws JavaModelException { } protected IBuffer openBuffer ( IProgressMonitor pm , Object info ) throws JavaModelException { } public IResource getResource ( ) { } public IResource resource ( ) { } protected abstract IResource resource ( PackageFragmentRoot root ) { } protected boolean resourceExists ( IResource underlyingResource ) { } public void save ( IProgressMonitor pm , boolean force ) throws JavaModelException { } public PackageFragmentRoot getPackageFragmentRoot ( ) { } protected abstract IStatus validateExistence ( IResource underlyingResource ) { } protected void openAncestors ( HashMap newElements , IProgressMonitor monitor ) throws JavaModelException { } }

Fix:
SelectionEngine engine = new SelectionEngine ( environment , requestor , project . getOptions ( true ) , owner ) ;